Musannaf Ibn Abi Shayba 13:1739

Abu Bakr narrated to us, he said: Shu'bah narrated to us, from 'Ammar, the companion of al-Sabiri, he said: I heard Sa'id ibn Jubayr being asked about *salam* (forward sale) in animals, and he forbade it. He (the questioner) said: "I was in Azerbaijan for two years, and we would see them doing it, and we would not forbid them." Sa'id said: "Would you scatter my seeds for someone who does not want them? Hudhayfah ibn al-Yaman used to forbid it."